Rotary well drilling device



March 29, 1966 R. P. VINCENT ROTARY WELL DRILLING DEVICE 4 Sheets-Sheet1 Filed Dec. 17, 1963 RENIC F. VINCENT INVENTOR.

ATTORNE Y March 29, 1966 R. P. VINCENT ROTARY WELL DRILLING DEVICE 4Sheets-Sheet 2 Filed Dec. 17, 1963 FIG. 6

RENIC P. VINCENT INVENTOR.

ATTORNEY March 29, 1966 Filed Dec. 1'7, 1963 R. P. VINCENT ROTARY WELLDRILLING DEVICE 4 Sheets-Sheet 3 RENIC R VINCENT INVENTOR,

ATTORNEY March 29, 1966 v c 3,243,001

ROTARY WELL DRILLING DEVICE Filed Dec. 17, 1963 4 Sheets-Sheet 4 36FIG.IOA F|G.|OB

\ INVENTOR.

RENIC P. VINCENT FIG-IO 8Y2! ATTORNEY.

United States Patent Delaware Filed Dec. 17, 1963, Ser. No. 331,153 16Claims. (Cl. 175-73) This application is a continuation-in-part of myapplication for Letters Patent of the United States, S.N. 159,630, filedDecember 15, 1961, now abandoned.

My invention concerns a tool for use in drilling wells by the rotarymethod. The tool controls the path of the drill. It utilizes thepressure of the drilling fluid to operate fluid motors which positionthe drill stem relative to the axis of the hole to guide the drill bitin the desired direction. The flow of high-pressure drilling fluid isdiverted to appropriate fluid motors by a unique pendulum and valvearrangement.

Rotary drilling rate is greatly handicapped in some areas owing to thepresence of geological formations which cause the drill bit to veer fromthe vertical. Such areas are commonly referred to as crooked holecountry. Several methods have been used to reduce the amount of holedeviation. For one thing, the amount of weight on the bit has beenreduced by keeping a greater than normal portion of the drill string intension. This decreases compressive forces and bending in the drillpipe. It has the disadvantage that the drilling rate drops appreciablywhen the weight on the bit is decreased. A method which is frequentlyused is that of placing additional drill collars and stabilizers in thelower end of the drill string to increase the stiffness of the drillstring, and to take advantage of the greater vertical force resultingfrom the greater concentration of weight near the bit. These methods aresuccessful to some extent; however, they do not permit full utilizationof the available weight on bit when drilling in crooked hole country."

On some occasions it is desirable to drill wells which are not vertical.In marine locations, several wells are sometimes drilled from a singleplatform with the wells angling out in different directions from theplatform. Also, where an oil-bearing formation is near the shore, thewells are sometimes drilled with the rig on the land and the well curvedso that the oil zone is penetrated below the water-covered area.Directional drilling is also used near salt domes to reach anoil-bearing structure at the flank of the dome without having to drillthrough the salt plug.

It is therefore an object of my invention to provide a rotary drillingtool which will maintain the drill bit on a desired course. In oneembodiment of my invention it is an object to provide a straight holedrilling tool which will reduce the tendency of the bit to drill offvertical. Another embodiment of my invention has for its object theprovision of a directional drilling tool which will force the bit todrill at a desired deviation from vertical. It is a further object toutilize a portion of the hydraulic power in the drilling fluid to guidethe bit along the desired path. Another object is to provide a valvesystem in this drilling tool which is substantially unaffected by normalrotary speeds of the drill pipe and by fluid flow through the tool.

My invention will be described by reference to the following drawingswhich illustrate various embodiments for reducing deviation fromvertical and for directional drilling.

FIGURE 1 is a view, in cross section, showing the arrangement of thevarious components of the tool.

FIGURE 2 is a sectional View at 22 in FIGURE 1, illustrating the valvesuspension element.

See

FIGURE 3 is a sectional view of the upper portion of the valve assembly,taken along line 3-3 in FIGURE 1.

FIGURE 4 shows the lower portion of the valve assembly at line 44 inFIGURE 1.

FIGURE 5, a sectional view along 5-5 in FIGURE 1, shows one embodimentof the pistons which force the bit toward a vertical alignment when thehole drifts off vertical.

FIGURE 6 shows a preferred design for ports in the drilling fluiddistribution system.

FIGURE 7 further illustrates the ports of FIGURE 6, and their associatedflow control equipment when the tool is positioned at a substantialdeviation from vertical.

FIGURE 8 is a sectional view of a portion of the tool arranged fordirectional drilling.

FIGURE 9, a sectional view at 99 in FIGURE 8, illustrates one of theplates which can be used in the directional drilling tool.

FIGURE 10 illustrates a vertical section of a portion of the toolshowing a preferred piston arrangement.

FIGURE 10A is an enlarged fragmentary section illustrating meansattaching the bearing member to the end of the piston shown in FIGURE10.

FIGURE 10B is a surface view of the outboard end of the fragmentarysection of FIGURE 10A.

FIGURE 11 is a sectional view taken at line 1111 of the tool of FIGURE10.

Referring to the above figures for a description of the apparatus,pendulum 13 in housing 11 is supported on pliant cable 16. Perforatedplate 18, seated between couplings 2G and 21, anchors the cable andsupports the pendulum. At the lower end of the pendulum, ring 14connected to the pendulum by supports 15, is suspended a short distanceabove bottom 34 of housing 11. Ports 25, 25 and 25" provide fluid accessfrom housing 11 to conduits 27, 27 and 27" extending through the bottomof the housing. Orifices 26, 26 and 26" in the lower ends of theconduits provide a pressure drop when fluid is flowing through theconduits. Cylinders 28, 28 and 28 extend from the conduits, through theaxis of the tool to the opposite side of the housing. Piston 29 is shownin cylinder 28 in FIGURE 1. Similar pistons are in cylinders 28 and 28".A force transmitting member, such as push rod 30, transmits the movementof piston 29 to sleeve 12 surrounding the housing. As shown in FIGURES1, 5 and 8, each push rod is mounted in a recess in the outboard end ofeach piston. Each recess has a rounded bottom, and the inboard end ofeach push rod is rounded to fit the bottom of the recess so that thepush rod may rotate and prevent seizure with the inside of the sleeve.Each rod is inserted into a recess and ex tends outwardly toward theinside wall of sleeve 12 so that fluid pressure in the cylinder causesthe piston and push rod to move outwardly against the sleeve. The lengthof the push rods in their respective recesses are such, in respect ofthe clearance between housing 11 and sleeve 12, that the push rods aremaintained in place even though no fluid is flowing through the tool.The recesses may be tapered slightly toward the bottom, if desired, topermit a slight movement of the push rods therein. As shown in FIGURES10 and 11, an arrangement utilizing a diaphragm and roller bearing isemployed in connection with the pistons to transmit the force to thesleeve. This latter embodiment, described hereinbelow, has been foundpreferable to the push rods described above for use in tools forreducing deviation from the vertical and for directional drilling tools.

In FIGURE 4, it is seen that ports 25, 25' and 25" lie in a circle aboutthe axis of the tool with their centers spaced apart. Sleeve 12surrounding housing 11 is pivotally supported between upper end 23 ofthe housing and lower shoulder 22 of the coupling 20. Splines 35 betweencoupling 20 and lip 24 of the sleeve cause the sleeve to rotate with thetool. Wear rings 33 around the lower end of the sleeve reduce the wearon the sleeve as it rotates against the side of the well.

In using this tool with rotary drilling equipment, the tool is installedin the drill string, preferably immediately above the bit. Thus thedrill bit would be connected to lower joint 36 and the drill pipe ordrill collars would be attached at upper joint 37. Drilling fluid pumpeddown the drill pipe enters coupling 21 and passes through ports 19 inplate 18, then flows through ceupling 20 and housing 11. The drillingfluid flows around pendulum 13, then between ring supports 15 andthrough the center of ring 14. When the tool is vertical, the ringcovers the outer portions of ports 25, 25' and 25 as shown in FIGURE 3.In this position, the drilling fluid flows to each of the ports insubstantially uniform proportions. The pressure drop is approximatelythe same through each of orifices 26, 26, and 26" owing to this uniformdistribution of drilling fiuid. The fluid discharged at the orificespasses through the bit and circulates to the surface by way of theannular space between the drill tools and the well walls.

Fluid motors operated by the drilling fluid adjust the position ofhousing '11 in relation to sleeve 12 and the inclination of the well.The pressure of the drilling fluid in conduit 27 and cylinder 28displaces piston 29 toward the outer end of the cylinder owing to thelower pressure of the drilling fluid in the annulus. Push rod 39transmits the piston displacement to sleeve 12. In the neutral positionillustrated, substantially equal pressures are ap plied to pistons 29,29' and 29 whereby push rods 30, 31 and 32 exert equal forces againstsleeve 12.

When the well is not vertical, the housing is eccentric with respect tothe pendulum. Ring 14 does not cover an equal portion of ports 25, 25and 25". This produces a nonuniform distribution of drilling fluidthrough conduits 27, 27' and 27" and their orifices. The highestpressure will prevail in the conduit having the highest flow rate sothat the piston and push rod associated with that conduit will exert agreater pressure against sleeve 12 than the other pistons and push rods.The result is that housing 11 moves to a position which is eccentricwith respect to sleeve 12. For example, if the lower end of the housingwere moved to the right in FIGURE 1, port 25 would be uncovered,permitting an increase in the flow through conduit 27. The increasedfluid pressure would cause piston 29 to move to the right, thusdisplacing the housing toward the left side of sleeve 12. The over-alltendency is for the housing to be displaced in the direction wherein itbecomes concentric with the vertically aligned ring and pendulum. As thetool rotates in an inclined hole, ports 25, 25' and 25" rotate through apath eccentric to ring 14, thus alternately increasing and decreasingthe flow through each port. As a port approaches the high side of thehole, an increasingly greater portion of its area is obstructed by thering. The area covered, that is, the flow restriction, reaches a maximumwhen the port is at the highest side of the hole. As the port rotatesflrom the high side to the low side of the hole, it approaches thecentral open portion of the ring, thereby reducing the restriction toflow until the port reaches the low side of the hole where the greatestarea is unobstructed by the ring. When the deviation of the hole fromvertical is slight, there will be little variation in the distributionof fluid to the ports. At large deviations there are much greatervariations of flow through the ports which produce greater forcestending to move the housing into vertical alignment. The ports may bedesigned so that the flow through each conduit will vary from to 100percent of the total flow through the tool as the tool rotates at orabove a particular degree of inclination.

I have shown the movement of the pistons 29 in the cylinders 28 to beradially outward, parallel to the radius of housing 11 and againstsleeve 12, so that the sleeve is forced outwardly to an eccentricposition in respect of the housing in a direction approximately 180 fromthe direc tion of movement of the pendulum to an eccentric position inrespect of the housing. However, the cylinders may extend outwardly and/or the force transmitting members may move outwardly along a line.angularly displaced from the radius to displace the sleeve in a desireddirection, typically between about and 200 from the direction ofpendulum movement, depending upon the amount of lead or la-g required.For example, it might be desirable to provide a 10 lead to compensatethe lag caused by the resistance of the drilling fluid to the rotationof the pendulum.

FIGURES 6 and 7 illustrate a preferred design of the drilling fluidvalve assembly which produced the maximum force on the forcetransmitting members. In FIGURE 6, ring 14 is concentric with housing 11as when the tool is in a vertical position. "Ports 25, 25 and 25" arecovered in equal amounts by ring 14, thus equal pressure prevails in theconduits adjacent cylinders 28, 28' and 28". Each of the forcetransmitting members bears against sleeve 12 with approximately equalforce, thereby maintaining housing 11 concentric with sleeve 12. FIG-URE 7 shows the position of ring 14 in relation to ports 25, 25' and 25"when the tool is at an inclination whereby pendulum 13 hangs against theside of housing 11. Port 25 is entirely uncovered whereas ports 25' and25 are completely covered by ring 14. Thus the maximum pressureavailable is exerted at this time on sleeve 12 by push rod 30, whereaspush rods 31 and 32 are exerting practically no pressure. As the toolrotates in a clockwise direction with ring 14 remaining in asubstantially fixed position, port 25" moves into the central openingthrough ring 14, admitting an increasing amount of fluid to that port.Simultaneously port 25 moves to a position under the ring. In thismanner the force on push rod 30 is gradually diminished and that on pushrod 31 increased. When the inclination of the tool is at a smaller angleand ring 14 does not contact housing 11, none of the ports arecompletely closed or opened. Thus, the apparatus in FIGURE 7 at asmaller angle would shift ring 14 to the right a slight distance whereit would cover a portion of port 25, reducing the force on push rod 30.Additionally, ports 25' and 25" would be partly uncovered whereby pushrods 31 and 32 would exert a force opposing that of push rod 30. Fromthe foregoing it can be seen that the minimum angle of hole inclinationat which the maximum force will be developed to push the housing and bittoward the low side of the hole is a function of the length of thependulum and the difierence between the radius of the inner edge of ring14 and the radius of the outer edges of the ports. Thus, for a givenring and port design, the tool can be made to control deviation within asmaller angle by increasing the length of the pendulum.

This apparatus has been described with ports 25, 25' and 25" positionedto receive fluid through the center of ring 14. It should be understoodthat these ports can be arranged to receive drilling fluid around theoutside of ring 14. In such an arrangement, the ports should be inapproximately vertical alignment with the push rods, rather than offset180 as shown in FIGURE 1, in order that the force transmitting membersmay move outwardly against the sleeve 12 in a direction substantiallyopposite that of the pendulum movement with respect to housing 11.

On the other hand, the ring and ports may be arranged in relation to thepistons and push rods whereby the force pushes the housing away from thelow side of the hole. This arrangement will be useful in drillingdirectional wells. FIGURES 8 and 9 show an arrangement which can be usedto adjust the angularity of ports 25, 25' and 25" in relation to theircorresponding conduits 27, 27 and 27". The lower end of housing 11contains a stack of oriented plates of the type shown in FIGURE 9. Plate39 at the top of the stack has ports in the arrange-ment shown in FIGURE6 for eflicient valve action. Plates 4t), 41, 42, 43, and 44, which haveidentical shapes, are held in place below plate 39 by bolts 38. Theseplates are positioned in FIGURE 8 so that conduits 27, 27' and 27spiralthrough an angle of 180 between the inlet ports and cylinders 28, 28 and28". In FIGURE 9 it is seen that conduits 27, 27' and 27" have anelongated, curved cross section. The centers of the circular ends of thecross-section of the conduits are separated radially by an angle of 36so that the five plates can be stacked in the housing to produce acontinuous conduit which spirals through an angle of 180 and enabling anangular displacement of 180 between each port and its associatedcylinder. Thus, in the apparatus shown in FIGURE 9, when the drill stemis slanted so that the pendulum is near the right side of the housing,ring 14 clears port 25 and cove-rs ports 25' and 25". The increased flowof drilling fluid through conduit 27 produces an increased force betweenpush rod 3i) and housing 12.. This urges the housing and drill bitfurther in the direction which it has already moved from vertical. Thisembodiment of my invention is useful in maintaining a well in a divertedcourse. The plates would be bolted in the housing with substantially noangularity between them when it is desired to drill :a vertical well, Asmall angular displacement up to about between the ports and theirassociated cylinders can be set to compensate the lag of the pendulum inthe housing.

In using this tool for directional drilling, the well may be firstdiverted in the desired direction, for example, by placing a whipstockin the well. The drill string is then run into the well with thedirectional tool above the bit and drilling commenced off the face ofthe whipstock. When the tool is deflected in this manner, the pendulumwill operate the valve so that the push rods force the housing towardthe high side of sleeve 12 and the well, thus maintaining thedeflection.

Again referring to FIGURES 6 and 7, ports 25, and 25 have circular outeredges and cuspal inner edges composed of two circular segments. Theradius of curvature r of these edges is equal to that of the inner edgeof ring 14. Radial axes 45, and 45" of these ports are spaced 120 apartin the bottom of housing 11. In FIGURE 7, it is seen that the outer edgeof port 2E, for example, lies directly below the inner edge of ring 14when the outer edge of the ring touches the housing on radial axis 45 ofport 25. In this position, the inner edge of the ring also lies directlyabove the segments of the inner edges of ports 25' and 25 which arenearest port 25. In this manner the inner edge of ring 14 defines theposition of the remaining segments of the ports when the outer edge ofthe ring contacts the housing at radial axes 45' and 45" of ports 25'and 25", respectively. Thus, the circular outer edge of port 25 and theadjacent segments of the cuspal inner edges of ports 25' and 25" have acommon center of curvature, located on radial axis 45 a distance d fromthe axis of housing 11. Distance d is the maximum displacement oramplitude of ring 14 on the pendulum.

It is desirable for the shape of the ports to be such that approximatelyone-third of the area of each port is not covered when the ring isconcentric with the housing. This arrangement permits a substantiallyuniform rate of flow through the apparatus, regardless of the positionof the pendulum and ring.

A unique means for supporting the pendulum has been devised. Bothpivoted and journaled supports were found to be unsatisfactory. There isa substantial pressure drop across the pendulum and ring at the highrates of fluid circulation which must be used. The friction in thepivoted and journaled supports at the high pressure drop causes thependulum to tend to hang in one position as the tool is rotated. Iprefer to use a flexible support 6 which is substantially frictionlessand inelastic. Support cable 16 is composed of multiple strands of asmalldiameter wire or rod. The strands should be straight rather thantwisted to reduce stretch. Cable anchor 17 is adjusted so that ring 14swings free of housing bottom 34 while drilling fluid in flowing throughthe tool without permitting a substantial flow between the ring andbottom.

Another variation in design which can be used to obtain greater forcespushing housing 11 to the desired position with respect to sleeve 12 isthat of using multiple cylinders and fluid motors in communication witheach fluid conduit. The fluid motors operated from a common conduitshould be in longitudinal alignment to produce the maximum force againstsleeve 12. The piston and push rod in each cylinder will effectivelymultiply the force obtained with a single cylinder.

This apparatus is suitable for use with either gaseous or liquiddrilling fluids. The size of orifice 26 can be selected to give thedesired pressure drop with the particular drilling fluid being used.

Turning now to FIGURES 10 and 11, the above-described tool employing analternate embodiment. of the force transmitting members has been foundto be highly advantageous. In FIGURE 11, which is an enlarged sectiontaken at line 11-11 of the housing shown in FIG- URE 10, only one piston51 has been shown in place in cylinder 52 for the purpose ofsimplification. However, it will be understood that in practice similarpistons 51' and 51 are positioned in cylinders 52 and 52", respectively.FIGURE 10A, an enlarged fragmentary section taken at the level ofbearings 56, and FIGURE 1013, i1- lustrate the manner of attachingroller bearing member 56 to the outboard end of each of the pistons. Inlieu of the piston and push rod design described above, the tool employsrelatively thin, large diameter pistons 51 which move radially incylinders 52, being actuated by fluid pressure in the correspondingconduits as described above. This piston arrangement enables a higherforce to be applied to the sleeve for a given fluid pressure, whilerequiring a significantly lower pressure drop across the tool.Preferably, the pistons are fabricated from a mild steel, and steellines 53 are employed in the cylinders 52 to reduce wear on thecylinders. Each cylinder is shaped to retain a flexible diaphragm member54, typically a %-inch-thick neoprene diaphragm is placed on the inboardside of the pistons 51 and fitted tightly into the enlarged portion ofeach cylinder to provide a fluid-tight seal in the cylinder and preventthe escape of drilling fluid through the cylinders. On the outboard endof each piston there is positioned a roller bearing member 56 which maycomprise parallel roller bearings positioned vertically on the pistonand held in place by keepers 57. If desired, multiple short rollerbearings may be employed in lieu of long rollers. Roller bearings 56 arepositioned in elongated recesses 58 extending vertically along theoutboard end of the pistons. Preferably, the back side of each recess iscurved, with a radius the same as the radius of the sleeve 12 to enablepistons 51 to move in and out of the cylinders without rolling from sideto side when the rollers engage the inside wall of the sleeve. Asbefore, the movement of pendulum 13 and ring 14 apportions drillingfluid through the orifices and conduits, and the fluid pressure in thecylinders actuates the pistons therein to drive the pistons outwardly.The roller bearings contact the sleeve and transmit the outward forcethereto so that the position of housing 11 is adjusted in relation tosleeve 12 as described hereinabove. Since this latter piston arrangementenables the tool to operate with a lower fluid pressure drop across thetool, central conduit 58 may be provided to provide adequate flow ofdrilling fluid to the bit. If desired, bumper ring 59 may be employed onthe lower end of pendulum 13, utilizing O-rings 60, as shown, to absorbthe impact of the pendulum striking the housing.

It can be seen that various modifications are possible within the spiritof my invention.

Therefore, I do not Wish to be limited to the specific embodimentsdisclosed herein. My invention should be construed according to thefollowing claims.

I claim:

1. An apparatus for controlling the attitude of a drill pipe during thedrilling of a well comprising:

a housing adapted to be installed in said drill pipe to form a portionthereof,

a sleeve surrounding said housing, said sleeve having an inside diametergreater than the outside diameter of said housing,

means for supporting the upper end of said sleeve on said housingwhereby the lower end of said sleeve can be displaced radially from saidhousing,

fluid conduits through said housing,

gravity-sensitive means supported from said housing for apportioningdrilling fluid flowing through said drill pipe to said fluid conduits inrelation to the attitude of said housing, and

pressure-responsive means carried by said housing acting substantiallyradially to said housing for applying outward pressure on said sleeveproportional to fluid pressure in said conduits to force said housingoutward in response to the position of said gravity-sensitive means.

2. An apparatus for controlling the attitude of a drill pipe during thedrilling of a well comprising:

a housing adapted to be installed in said drill pipe and form a portionthereof,

a sleeve surrounding said housing, said sleeve having in inside diametergreater than the outside diameter of said housing,

means for supporting the upper end of said sleeve on said housing,whereby the lower end of said sleeve can be displaced radially from saidhousing,

fluid conduits through said housing,

a pendulously supported gravity-sensitive, multiple opening valvecarried by said housing for apportioning drilling fluid flowing throughsaid drill pipe to said fluid conduits in relation to the attitude ofsaid housing, and

a plurality of fluid actuated motors carried by said housing, eachconnected to one only of said fluid conduits and adapted to apply radialpressure on said sleeve proportional to fluid pressure in said conduitsto urge said housing away from said sleeve in response to the positionof said gravity-sensitive means.

3. An apparatus for controlling the attitude of a drill pipe duringthedrilling of a well comprising:

a housing,

a sleeve surrounding said housing, said sleeve having an inside diametergreater than the outside diameter of said housing,

means for pivotally supporting the upper end of said sleeve on saidhousing whereby the lower end of said sleeve can move to a positioneccentric to said housing,

fluid conduits through said housing, pendulum-actuated means in saidhousing for apportioning drilling fluid to said fluid conduits inrelation to the attitude of said housing,

means for restricting fluid discharge from said conduits,

multiple cylinders in said housing, at least one of said cylinderscommunicating with each of said conduits, and pistons in said cylindersadapted for lateral extension from said housing to bear against saidsleeve and move said housing in relation to the position of saidpendulum-actuated means as fluid flows through said conduits.

4. The apparatus of claim 3 wherein said pendulumactuated means forapportioning drilling fluid includes:

a pendulum pliantly supported in said housing along the longitudinalaxis thereof, i

a ring attached to the lower end of said pendulum, the lower surface ofsaid ring lying in a plane parallel and in proximity to that of thebottom of said housing, the center of said ring lying on thelongitudinal axis of said pendulum,

three fluid ports near the bottom of said housing beneath said ring andspaced apart therefrom to provide fluid access to said fluid conduits,said ports being substantially uniformly spaced in a circle about theaxis of said housing, each of said ports having a circular outer edgeand a cuspal inner edge consisting of two circular segments, each ofsaid circular outer edge and inner edge segments having a radius equalto that of the inner edge of said ring, the center of curvature of saidouter edge being in longitudinal alignment with the axis of saidpendulum when said pendulum is displaced along the radial axis of saidport the maximum possible distance from the axis of said housing, andthe centers of curvature of said cuspal circular segments lying on theradial axes of adjacent ports when said pendulum is displaced themaximum distance along those radial axes.

5. Apparatus for controlling the attitude of a drill pipe during thedrilling of a well comprising:

a housing,

a sleeve surrounding said housing, said sleeve having an inside diametergreater than the outside diameter of said housing,

means for pivotally supporting the upper end of said sleeve on saidhousing whereby the lower end of said sleeve can move to a positioneccentric to said housing,

fluid conduits through said housing,

a mass pliantly supported in said housing along the longitudinal axisthereof, fluid ports near the bottom of said housing beneath said massand uniformly spaced in a circle about the axis of said housing, and aring attached to the lower end of said mass and above said fluid portswhereby said ring alternately restricts fluid flow to said ports whensaid apparatus is rotated out of vertical alignment to apportiondrilling fluid to said fluid conduits in relation to the attitude ofsaid housing,

means for restricting fluid discharge from said conduits,

multiple cylinders in said housing, at least one of said cylinderscommunicating with each of said conduits, and pistons in said cylindersadapted for lateral extension from said housing to bear against saidsleeve and move said housing in relation to the position of saidpendulum-actuated means as fluid flow through said conduits.

6. An apparatus for controlling the attitude of a drill pipe during thedrilling of a well comprising:

a cylindrical housing having a fluid inlet at the top and asubstantially flat bottom,

a sleeve pivotally mounted on said housing and positioned around saidhousing, said sleeve having an inside diameter greater than the outsidediameter of said housing and adapted for eccentric displacement inrelation to said housing,

multiple cylinders in said housing with the axes of said cylindersnormal to the axis of said housing,

a piston in each of said cylinders, said pistons being extensible toengage said sleeve,

multiple drilling fluid conduits through thebottorn of said housing,each of said conduits communicating with at least one of said cylinders,

an inlet port for each of said conduits, said ports lying in a circle inthe bottom of said housing about the axis of said housing,

flow restricting outlets in said conduits,

a pendulum pliantly-supported in said housing,

a port closure ring attached to said pendulum whereby each of said inletports is covered an equal amount when said pendulum is axially alignedin said housing and the total area covered at any pendulum positionbeing approximately equal to the area of one port.

7. The apparatus of claim 6 wherein said pliantlysupported pendulumincludes:

a mass and a bundle of substantially inelastic, flexible fibers adatpedto support said mass in said housing.

8. In the drilling of wells by the rotary method, an apparatus tocontrol the deviation of the well from vertical comprising:

a housing, a loose-fitting sleeve surrounding said housing, the upperend of said sleeve being pivotally attached to the upper end of saidhousing whereby the lower end of said sleeve can move to a positioneccentric to said housing,

multiple ports in the bottom of said housing uniformly spaced in acircle about the axis of said housing,

a fluid conduit extending from each of said ports through said housing,

a flow restriction at the outlet of each fluid conduit,

multiple cylinders in said housing with the axes of said cylinderssubstantially perpendicular to the longitudinal axis of said housing, atleast one of said cylinders in fluid communication with each of saidconduits, each cylinder angular-1y displaced substantially 180 from itsassociated port,

pistons in said cylinders,

force transmitting members on the outboard ends of each of said pistonsfor radial engagement with said sleeve,

a pendulum in said housing,

a pliant support for said pendulum, said support being anchored on thelongitudinal axis of said housing,

a ring supported from the lower end of said pendulum and covering theouter portions of said ports when said tool is in the vertical position,the center of said ring being on the longitudinal axis of said pendulum,

means for passing drilling fluid to said ports,

a flat, lower face on said ring in flow-controlling relationship to saidports to control the flow of drilling fluid to said ports, wherebydeviation from the vertical during drilling urges said sleeve outwardlyfrom said housing in a direction substantially opposite from thedirection of movement of said pendulum with respect to said housing.

9. The apparatus of claim 8 wherein said force transmitting memberscomprise push rods in the outboard end of each said pistons.

10. The apparatus of claim 8 including a diaphragm member in each saidcylinders on the inboard side of the pistons positioned therein, saiddiaphragm member be ing actuated by fluid pressure to contact saidpiston and move said piston outwardly in its associated cylinder.

11. The apparatus of claim 10 wherein said force transmitting meanscomprises a roller bearing member on the outboard end of each of saidpistons.

12. In the drilling of wells by the rotary method, an apparatus fordefiecing the drill from a straight path comprising:

a housing,

a sleeve surrounding said housing and piovtally attached to the upperend of said housing whereby said sleeve can move to a position eccentricto the lower end of said housing,

multiple ports in the bottom of said housing,

multiple cylinders in said housing, each connected to one of said portsand angularly displaced substantially 180 from its associated port,

the axes of said cylinders being perpendicular to the axis of saidhousing,

pistons in said cylinders adapted to be radially displaced by fluidflowing through said apparatus,

force transmitting members on the outboard ends of said pistons fortransmitting the movement of said pistons to said sleeve and to displacesaid sleeve to said eccentric position,

multiple conduits in said housing connecting each of said ports with itsassociated cylinder inboard of said pistons,

means for restricting fluid discharge from said conduits,

a pendulum in said housing,

a pliant support for said pendulum anchored on the longitudinal axis ofsaid housing, and

a ring attached to the lower end of said pendulum and positioned in aplane parallel to the bottom of said housing whereby the flow of fiuidthrough said ports is controlled by the position of said ring andpendulum,

the movement of said pendulum during drilling producing an eccentricityof said housing in said sleeve approximately 180 displaced from theeccentricity of said pendulum in said housing.

13. The apparatus of claim 12 including:

a stack of circular plates secured in the bottom of said housing, eachof said plates being provided with multiple elongated, curved openingsextending therethrough, said openings being in flow communication withcorresponding openings in adjacent plates to form continuous spiralconduits connecting each of said ports with its associated cylinder.

14. The apparatus of claim 12 wherein said force trans mitting memberscomprise push rods in the outboard end of each of said pistons.

15. The apparatus of claim 12 including a diaphragm member in each saidcylinders on the inboard side of the pistons positioned therein, saiddiaphragm member being actuated by fluid pressure to contact said pistonand move said piston outwardly in its associated cylinder.

16. The apparatus of claim 15 wherein said force transmitting meanscomprises a roller bearing member on the outboard end of each of saidpistons.

References Cited by the Examiner UNITED STATES PATENTS 2,075,064 3/ 1937Schumacher et al. l231 2,153,680 4/1939 Schumacher et a1. 231 3,043,3817/1962 McNeely 175-73 3,141,512 7/ 1964 Gaskell et al 17573 X CHARLES E.OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

1. AN APPARATUS FOR CONTROLLING THE ATTITUDE OF A DRILL PIPE DURING THEDRILLING OF A WELL COMPRISING: A HOUSING ADAPTED TO BE INSTALLED IN SAIDDRILL PIPE TO FORM A PORTION THEREOF, A SLEEVE SURROUNDING SAID HOUSING,SAID SLEEVE HAVING AN INSIDE DIAMETER GREATER THAN THE OUTSIDE DIAMETEROF SAID HOUSING, MEANS FOR SUPPORTING THE UPPER END OF SAID SLEEVE ONSAID HOUSING WHEREBY THE LOWER END OF SAID SLEEVE CAN BE DISPLACEDRADIALLY FROM SAID HOUSING, FLUID CONDUITS THROUGH SAID HOUSING,GRAVITY-SENSITIVE MEANS SUPPORTED FROM SAID HOUSING FOR APPORTIONINGDRILLING FLUID FLOWING THROUGH SAID DRILL PIPE TO SAID FLUID CONDUITS INRELATION TO THE ATTITUDE OF SAID HOUSING, AND PRESSURE-RESPONSIVE MEANSCARRIED BY SAID HOUSING ACTING SUBSTANTIALLY RADIALLY TO SAID HOUSINGFOR APPLYING OUTWARD PRESSURE ON SAID SLEEVE PROPORTIONAL TO FLUIDPRESSURE IN SAID CONDUIT TO FORCE SAID HOUSING OUTWARD IN RESPONSE TOTHE POSITION OF SAID GRAVITY-SENSITIVE MEANS.